Optical system for projecting machines



June 12, 1934. J. MIHALYI 1,962,356

OPTICAL SYSTEM FOR PROJECTING MACHINES Filed March 28, 1933 anormqa/Patented June 12, 1934 PATENT OFFICE OPTICAL SYSTEM FOR PROJECTINGMACHINES Joseph Mihalyi, Rochester, N. Y.;' assignor to Eastman KodakCompany, Rochester, N. Y., a corporation of New York Application March28, 1933, Serial No. 663,111 Claims. (CI. 88-24) This invention relatesto projectors and more particularly to means for adjusting the elementsof a projection system relative to each other. One object of myinvention is to provide a simple 5 inexpensive and efiicient means foradjusting a reflector relative to a light source and relative to acondensing system. Another object of my invention is to provide a simpleadjustment by which a reflector may be regulated axially andeccentrically with respect to a light source. An-

other object of my invention is to provide a single threaded connectionbetween a reflector unit and a support through which a reflector may bemoved both to and from a light source and eccentrically with respectthereto and other objects will appear from the following specification,the novel features being particularly pointed out in the claims at theend thereof.

Coming now to the drawing wherein like reference characters denote likeparts throughout;

Fig. 1 is a fragmentary view through a lamp house and optical systemconstruction in accordance with and embodying a preferred form of myinvention; I

Fig. 2 is a fragmentary sectional view showing the reflector inelevation;

Fig. 3 is a perspective view of the reflector unit removed from the lamphouse.

The reflector and optical system construction in accordance with myinvention may be employed in any case where it is desired to project abeam of light. 7 Such a' beam of light can be advantageously used inconnection with a motion picture projector, in connection with aprojector for lantern slide work, or in connection with any othermachine in which a collimated beam of light is required.

As a specific embodiment of my invention 1 have shown an optical systemof a simple type used in connection with a lamp house suitable formotion picture or slide projection work.

In Fig. 1 there is a support or lamp house 1 carrying a base 2 having alamp 3 supporting a grid filament 4 such as is well known. The lamp 3and 5-. the base 2 are preferably of the pre-focus type as is also wellknownso that the filament 4 will always occupy a fixed position withrespect to the is so positioned with respect to the lamp that the axispasses through the center of the filaments 4. In Fig. 1 the axis of thecondenser elements and filament is indicated by the dot and dash line A.

Opposite to the tubular extension on the lamp house there is a secondtubular extension 10 which is axially arranged with respect to the axisA and which is internally threaded at 11. I This tubular extension formsa support for the reflector unit which is broadly designated by thenumeral 12. As best shown in Fig. 3, the reflector unit 12 comprises atubular member 13 having a knurled ring 14 on the outside and having aring 15 formed upwardly from the tubular part 16 a suflicient distanceto carry a thread 1'7. The ring 15 is not concentric with respect to thetubular member 16 and in Fig. 3 the distance (a) from the thread to oneside of the ring is considerably less than the distance (b) from thethread to the other side of the tubular mount 16. In other words, thering 15 is an eccentric ring so that the thread 17 is eccentric withrespect to the reflecting unit as a whole. Thus when the reflecting unit12 is turned by means of the knurled ring 14, the reflector 19 is movedboth 30 to and from the .lamp filament 4 and the axis of the reflector19 is moved parallel to the axis A of the condenser unit eccentricallywith respect thereto.

The reflecting element may consist of a con- 35 cave mirror surfacedwith silver as is customary in projecting machines and this mirror isheld onto the reflecting unit 12 in any suitable manner.

In projecting systems where the'lamp filament 9o 4 is fixedly mountedwith respect to the base and where the condensers are fixedly mountedwith respect to the base it is desirable to move a reflector only a veryshort distance to and from the lamp and a very short distance to andfrom the axis of the condenser so that when slight variations'in theposition of the filament 4 with respect to the lamp base 2 may be takencare of.

It is also desirable to move the reflector a comparatively slightdistance about the axis A since it is desirable, as indicated in Fig. 2,to adjust the reflector into a position in which the reflected lampfilaments 4 appear to lie between the actual lamp filaments 4, thusmaking a comparatively solid square area of brilliantly illumisingleadjustment as above described adequately takes care of properly focusingthe lamp filaments for most efiicient use.

With an optical system as above described the set screw 20 may bereleased after a new lamp has been placed in the lamp house and theknurled ring 14 may be turned so that the reflector will move to andfrom the filaments 4. The threads 17 and 11 are comparatively finethreads so that at each revolution of the reflecting unit 12 thereflector 19 moves a comparatively short distance along the axis A. Atthe same time the reflector 19 is moved eccentrically with respect tothe axis A and when the reflector filaments 4 are in the correctposition with respect to the filaments 4 the set screw 20 may betightened to hold the reflector in the desired position.

It will thus be seen that I have provided an extremely simple adjustmentfor a reflector by which movement in one direction actually takes careof an adjustment in two directions. The eccentric ring which I haveshown in the drawing permits the reflector 19 to move a distancesufiicient to take care of the proper focusing of the commercial type ofpre-focus lamp when inserted in a pre-focus base of the commercialvarieties now obtainable.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an optical system for projection purposes, the combination with alamp having filaments, a condensing lens associated therewith and areflector adapted to reflect the lamp filaments, said reflectorcomprising a unit including a threaded annular member carrying saidreflector eccentrically mounted with respect to said annular member, athreaded mount for the annular member,

whereby the reflector may be moved through the threaded mount withrespect to the lamp filaments.

2. In an optical system for projection purposes, the combination with alamp having filaments, a condensing lens associated therewith and areflector adapted to reflect the lamp filaments, said reflectorcomprising a tubular device having a reflector and a threaded areaeccentrically positioned with respect to each other, a threaded memberfixedly mounted with respect to said lens, and adapted to receive thethreaded area of the reflecting unit whereby the reflector may be movedeccentrically and to and from said lamp upon said threads.

3. A reflecting unit for optical systems comprising a tubular element, aconcave reflector mounted therein, a threaded ring carried by thetubular element, said threaded ring being eccentric with respect to thetubular element and reflector.

4. A reflecting unit for optical systems comprising a tubular element, areflector mounted inside of said tubular element and coaxially therewithan eccentric ring carried by the tubular element and a thread on theeccentric ring.

5. In an optical system the combination with a support, of a lampfixedly mounted with respect to said support, a threaded opening in saidsupport having a fixed relation to said lamp, a reflector unit includinga reflector, and an eccentric ring having a fixed relation to thereflector, said eccentric ring including a thread adapted to engage thethreaded opening in the support whereby said reflector may be moved intwo direct-ions with respect to said lamp on said threads.

JOSEPH MIHALYI.

